Well pipe elevatok



.Sept. 21, 194 8 c. A. LUNDEEN m1. PIPE ELEVATOR Fiied April 6, 1945 Patented Sept. 21, 1948 WELL PIPE ELEVATOR Chester A. Lundeen. Les Angeles, Call! assignmto Byron Jackson (20., Vernon, CaliL, a corporation of Delaware Application April 6, 1945, Serial No. 586,888

This invention relates to well pipe elevators such as are used for handling drill pipe, well casing and tubing, and relates particularly to improvements in elevators of the so-calle center latch" type.

The term "center latch is applied to elevators of the type comprising. a pair of substantially symmetrical sections having semi-cylindrical mating recesses which cooperate to define a pipereceiving recess, the two sections being pivotally connected together at the rear side of the pipe recess and having cooperating latch means at the front side. each section having a supporting ear for supporting the elevator by a pair of links. The supporting ears are so located that the points of supporting engagement by the links lie in a transverse plane passing through the center ,of the pipe recess and extending substantially perpendicular to a plane through the pivotal axis and the center of the pipe recess. Because of this construction, the ears are spread farther apart as the elevator sections are swung outwardly about their pivotal connection. thus moving the lower ends of the elevator links outwardly from their normal suspended positions. The tendency of the links to return to their normal suspended positions exerts a force on the elevator sections urging them in closing direction, and thus it is necessary to make some provision for retaining the elevator sections in open position as the elevator is raised or lowered in the derrick preparatory to being latched onto a stand of pipe.

It has been customaryto tilt the forward side of the elevator downwardly in order to cause the weight of the elevator to exert a spreading force on the sections in opposition to the closingforce exerted by the links,-and thus maintain the elevator open. This practice is, however, subject to the objection that it becomes necessary for the operator to raise the forward side of the elevator when applying it to the pipe. M

It is a principal object of this invention to provide improved means for releasably retaining the sections'of a well pipe elevator in open posi-' tion.

It is a further object of this invention to provide simple, rugged and dependable means acting between the sections of an elevator to exert a force of predetermined magnitude holding the sections in open position. this force being only sufiicient to prevent inadvertent closing of the sections by vibration or jarring. and being rendered ineffective upon initial closing movement of the sections by the operator.

A still further object of this invention is to IClaim. (01. 294-90) provide elevator spreading means so constructed and arranged as to be protected against damage resulting from rough handling while in use or in transit or storage.

The manner in which the foregoing :and other objects are attained will 'be apparent from the following detailed description of a preferred embodiment of the invention, reference being had to the accompanying drawing wherein:

Fig. 1 is a top plan view of an elevator in closed position and embodying the invention, with parts broken away substantially in the plane of section line IIIlII of Fig. 6 to disclose the spreading means;

Fig. 2 is a view similar to Fig. 1 but showing the elevator releasably latched in open position;

Fig. 3 is a fragmentary view on anenlarged scale. taken substantially on line III-III of Fig. 6, with the elevator sections in closed position:

Fig. I is a view similar to Fig. 3 but showing the sectionslatched in open position;

Fi 5 is a vertical section taken on line V-Y of Fig. 3; and

Fig. 6 is a vertical section taken on line VI-VI of Fig. 1.

Referring to the drawing, the. invention is depicted therein as applied to a center latch elevator constructed substantially in accordance with the disclosure of my Patent No. 2,257,120, dated September 30. 1941, for Well pipe su port. The elevator comprises generally apair of sections I and 2 provided with semi-circular bores 3 and l which cooperate to define a circular pipe recess.- The sections are pivotally connected by a hinge pin 5 engaging upper and lower hinge lugs 6 and 6' on the section I and hinge lug I on the section 2 at the rear side of the pipe recess. Latch means, generally designated 8, is provided for releasably' latching the sections together about a pipe. Reference may be had to my ai'orernentioned"Patent No. 2,257,120 for a detailed description of the latch means. Supportin ears 9 and-l0 project laterally from the respective sections. and are so disposed as to be engaged by the usual elevator links at points lying in a transverse vertical plane extending through the center of the pipe recess. As shown in Fig. 6. each ear comprises an upper lug II and a lower lug II, the outer ends of which are connected by a block I! (Figs. 1 and 2) to retainthe link' in the recess between the lugs.

Referring now to my improved spreading means, it will be observed that the lower lug I 2 0f the supporting car on the right-hand elevator section 2 is recessed to provide a chamber tor a a pin l8 extending between the forks of the frame the lug I! on a pivot pin it for limited oscillation about a vertical axis. A roller I1. is Journaled on It, and has rolling contact with a cam mg I! formed integrally with the lower hinge lug 8' of the elevator section I. The frame ll ls constantly urged in a clockwise direction about the axis of the pin it by a compression spring 20. to maintain the roller II in engagement with the cam lug l9 and to yieldingiy resist counterclockwise movement of the roller and forked frame when the roller engages a cam surface 2i at the end of the cam lug (see Fig. 4)

Referring particularly to Figs. -3 and 4 of the drawing. it will be observed that the peripheral surface of the cam lug I9 is concentric with the hinge pin 5, and consequently as the roller I'I moves along this surface of the lug during Opening and closing movements of the elevator sections, the position of the forked frame I! does not change and the force exerted by the spring 20 remains constant. However, when the elevator sections are spread apart to the relative positions shown in Figs. 2 and 4, the roller l1 leaves the peripheral surface of the cam lug and rides inwardly along the cam surface it under the influence oi' the spring 20. In order to permit the elevator sections to be swung inwardly from this -position, the roller i1 and its supporting frame it must be forced outwardly away from the axis of the-hinge pin 5 by the cam surface 2|, against the force of the spring 20. The sections are thus reieasably latched in open position. By varying the shape of the cam surface 2! and by selecting a spring of suitable compressive strength, the force required to be exerted by the operator on the manipulating handles of the elevator, to cause the cam surface to retract the roller and permit closing of the elevator sections, may be varied at will. It will be apparent that after the roller has i been retracted and engages the peripheral surface of the cam lug, the force exerted by the spring 20 is no longer effective to restrain the sections against closing movement.

It should be noted that the operative parts of the spreading latch are fully housed within the recess in the lug I2, and are thus protected against damage by accidental blows. The parts are few in number. and are sufliciently rugged and free from excessive wear so that they-may .be relied on to operate properly during the entire useful life of the elevator.

It will be apparent that various changes may be made in the construction and the arrangement of parts without departing from the spirit of the invention or the scope of the appended claim.

I claim:

In a well pipe elevator, a pair of pipe encircling nection between said members and acting on said 1 frame in line with said roller, said frame, roller, and resilient means being within the boundaries of and protected by said member. a cam on the other of said members comprising a portion concentric to the pivot axis of said members and a portion extending in a direction having its major component radial to said axis, said latter portion being engageable with said roiic'r when said membets are in open'position to yieldingly retain said members in open position, said latter portion of said cam being disposed and arranged to force said roller away from said axis against the action of said spring means upon application of a force of predetermined magnitude to said members in closing direction.

CHESTER A. LUNDEEN.

REFERENCES CITED The following referenced are of record in the file of this patent:

UNITED STATES PATENTS Name Date 

